The battery safety valve, also known as the battery exhaust valve, is a valve that acts as a safety protection valve on a valve-controlled battery. When the battery is working, the internal pressure of the battery is gradually increased due to the internal reflection of the released gas. When the pressure reaches the valve opening threshold, the safety valve automatically opens to discharge the gas. After the internal pressure of the battery drops to the valve closing threshold, the safety valve automatically closes. At the same time, during this process It can prevent external gas from entering the battery and acid splashing in the battery. It can avoid the bulging and explosion caused by excessive pressure in the battery or the oxidation failure of the battery reaction solution caused by the entry of external gas into the battery.